If you are a sports fan with a taste for risk, you can bet on games, legally and illegally. Or you can play fantasy sports, managing players based on their real-life statistics. And now, Wall Street has come along with a way to buy a stake in an athlete's performance. The public will be able to buy stock in at least two NFL players, sort of.

Sportswriter Stefan Fatsis joins us now, as he does most Fridays, to explain this. Hi, Stefan.

STEFAN FATSIS: Hey, Robert.

SIEGEL: Yesterday, a company called Fantex announced its second planned public offering in an athlete: Vernon Davis, a star tight end with the San Francisco 49ers. A few weeks ago, it cut a similar deal with running back Arian Foster of the Houston Texans. Explain how this works.

FATSIS: Well, Fantex is a start-up backed by Wall Street and Silicon Valley executives. It's a year old. It's losing money. The basic idea is that it will pay athletes a lump sum in exchange for a percentage of their future sports-related income: playing contracts, endorsement deals, broadcasting deals.

Fantex says it's agreed to pay Foster $10 million for 20 percent of his earnings and Davis $4 million for 10 percent of his. In return, Fantex said it's going to help manage the athletes' brand. But the part of the arrangement that's gotten the most attention involves selling shares in Foster's and Davis' brand to the public.

SIEGEL: So, selling stock in Arian Foster and Vernon Davis, which I imagine is where Fantex plans to get the $14 million to pay the players.

FATSIS: Yeah, exactly. These deals don't happen unless Fantex raises the money from investors, better known as fans. The fans then would be buying what's called a convertible tracking stock, which will trade on a closed proprietary market run by Fantex itself. As the value of the brand changes, the stock should rise and fall. Investors buy and sell. But there are a whole lot of caveats.

SIEGEL: I bet. I don't think we have enough time for all the caveats...

FATSIS: No, we don't.

SIEGEL: ...but why don't you give us a sample?

FATSIS: Well, for the Arian Foster deal, the company filed a 150-page offering with the SEC. Thirty-seven of those pages detailed risk factors. And here are just a couple. There might not be any liquidity in this market. Or the value of Arian Foster's brand might vanish. The website thestreet.com took a look. It concluded that investors wouldn't be investing in Arian Foster at all but rather in Fantex.

And that's because under the terms of this deal, shares in Arian Foster or Vernon Davis or any other athlete can be converted to common shares of this company, Fantex, whenever the company wants to. So investors won't own a piece of Foster's or Davis' brand but instead would own shares in Fantex.

SIEGEL: Well, using, say, the numbers that you had for the Foster deal, could the players actually earn enough money so that the company makes a profit from this investment?

FATSIS: I don't see how that's possible. Foster needs to earn $50 million to make this earn money for Fantex. He's due 25 million more on his contract. It expires at the end of 2016. He might not make it to the end of that contract. And the odds of another team giving him 25 million at the age of 30 are near zero. He's a smart guy, a marketable guy. But his endorsement deals aren't going to be worth that much money, especially after he retires.

SIEGEL: Yeah. If I were investing in NFL football players, I wouldn't buy a running back, given the risk of injury. I'd buy a quarterback who might become a superstar.

FATSIS: Might become a superstar. And if you're that quarterback's agent, you have to be very, very careful about committing 10 or 20 percent of this player's future earnings to a company when he, in fact, might become the next Peyton Manning, who can earn millions of dollars from TV commercials and endorsements, not to mention tens of millions of dollars from playing the game.

SIEGEL: But do I understand that if I - if this deal existed and I could have bought, say, Troy Aikman when he was a quarterback for the Dallas Cowboys, I'd still be collecting from his salary as a commentator on NFL games?

FATSIS: I'm reading right now from the Securities and Exchange Commission offering that this company has filed in the Arian Foster deal, and it says that the brand contract is intended to be effected in perpetuity.